Sony KV-32HS500 Training Manual page 41

DA-4 Direct AC-Relay Shut-Off Protection Circuits
(INRUSH)
C6581
PH6002
R6709
D6702
D6501
RY6702
(INRUSH
RELAY)
FROM
AC RELAY
RY6701
R6705
Inrush Current Relay Protection Circuit
(Reference Figure 4-7)
The current rating of the AC relay (RY6701) is 117mA at 153VAC. To keep the current below 117mA, resistor
R6705 (Inrush Current Resistor) is in series with the AC input during the initial power-up of the TV. After the
initial power-up current surge, R705 is bypassed when RY6702 (Inrush Relay) is energized and the switch is
closed.
The operation of RY6702 is monitored using R6705 and PH6002. If RY6702 does not function, a voltage drop
will develop across R6705, which in turn develops a voltage across R6715. The voltage across R6715 turns on
the LED and 11V is output on PH6002/pin 3. D6523 is now forward biased and a High is applied to the base of
Q6504 turning it ON, which then applies a Low to the base Q6502 turning it ON. Q6504 and Q6502 is a latching
circuit.
FROM IC2300
(+15 OVP)
D6523
D6507
+
R6538
D6505
R6539
+15V
12V
4 3
1 2
R6715
D6518
11
T6703
12
12V
TO AC RECT.
D6702
FIGURE 4-7 - DA-4X DIRECT AC RELAY SHUT-OFF PROTECTION CIRCUIT
R6525
AC RELAY
R6504
Q6504
(B+ OCP) (B+ OVP)
D6526
TO
SYSCON
0V IC2300
1
IC6502 IC6502
-
+
3 2
0.7V
REF.
5V
+135V
R6519
+
C6553
R6520
R6506
39
4. DA-4 & DA-4X Protection Circuits
D6524
R6523
R6526
Q6502
+
C6575
D6525
+135V
0V
FROM T508/
7
R6535
-
+
R6536
6 5
R6516
2.4V
C572
REF.
5V
R6517
D6522
4.7V
G-BOARD
TO AC RELAY
RY6701
Q6503
R6528
R6527
(AC PROT.)
D6527
CN6505
2
2
CN901
PIN 8
D528
5.1V
D529
Q528
R634
11V
R561
+
R605
A-BOARD
C31P15-4-7 1520 11/15/02